1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2022, STMicroelectronics
4 * Copyright (c) 2016, Linaro Ltd.
5 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
6 * Copyright (c) 2012, PetaLogix
7 * Copyright (c) 2011, Texas Instruments, Inc.
8 * Copyright (c) 2011, Google, Inc.
10 * Based on rpmsg performance statistics driver by Michal Simek, which in turn
11 * was based on TI & Google OMX rpmsg driver.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 #include <linux/cdev.h>
17 #include <linux/device.h>
19 #include <linux/idr.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/poll.h>
23 #include <linux/rpmsg.h>
24 #include <linux/skbuff.h>
25 #include <linux/slab.h>
26 #include <linux/uaccess.h>
27 #include <uapi/linux/rpmsg.h>
29 #include "rpmsg_char.h"
30 #include "rpmsg_internal.h"
32 #define RPMSG_DEV_MAX (MINORMASK + 1)
34 static dev_t rpmsg_major;
36 static DEFINE_IDA(rpmsg_ept_ida);
37 static DEFINE_IDA(rpmsg_minor_ida);
39 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev)
40 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev)
43 * struct rpmsg_eptdev - endpoint device context
44 * @dev: endpoint device
45 * @cdev: cdev for the endpoint device
46 * @rpdev: underlaying rpmsg device
47 * @chinfo: info used to open the endpoint
48 * @ept_lock: synchronization of @ept modifications
49 * @ept: rpmsg endpoint reference, when open
50 * @queue_lock: synchronization of @queue operations
51 * @queue: incoming message queue
52 * @readq: wait object for incoming queue
58 struct rpmsg_device *rpdev;
59 struct rpmsg_channel_info chinfo;
61 struct mutex ept_lock;
62 struct rpmsg_endpoint *ept;
64 spinlock_t queue_lock;
65 struct sk_buff_head queue;
66 wait_queue_head_t readq;
69 int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
71 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
73 mutex_lock(&eptdev->ept_lock);
75 rpmsg_destroy_ept(eptdev->ept);
78 mutex_unlock(&eptdev->ept_lock);
80 /* wake up any blocked readers */
81 wake_up_interruptible(&eptdev->readq);
83 cdev_device_del(&eptdev->cdev, &eptdev->dev);
84 put_device(&eptdev->dev);
88 EXPORT_SYMBOL(rpmsg_chrdev_eptdev_destroy);
90 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
93 struct rpmsg_eptdev *eptdev = priv;
96 skb = alloc_skb(len, GFP_ATOMIC);
100 skb_put_data(skb, buf, len);
102 spin_lock(&eptdev->queue_lock);
103 skb_queue_tail(&eptdev->queue, skb);
104 spin_unlock(&eptdev->queue_lock);
106 /* wake up any blocking processes, waiting for new data */
107 wake_up_interruptible(&eptdev->readq);
112 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
114 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
115 struct rpmsg_endpoint *ept;
116 struct rpmsg_device *rpdev = eptdev->rpdev;
117 struct device *dev = &eptdev->dev;
124 ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
126 dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
132 filp->private_data = eptdev;
137 static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
139 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
140 struct device *dev = &eptdev->dev;
142 /* Close the endpoint, if it's not already destroyed by the parent */
143 mutex_lock(&eptdev->ept_lock);
145 rpmsg_destroy_ept(eptdev->ept);
148 mutex_unlock(&eptdev->ept_lock);
150 /* Discard all SKBs */
151 skb_queue_purge(&eptdev->queue);
158 static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
160 struct file *filp = iocb->ki_filp;
161 struct rpmsg_eptdev *eptdev = filp->private_data;
169 spin_lock_irqsave(&eptdev->queue_lock, flags);
171 /* Wait for data in the queue */
172 if (skb_queue_empty(&eptdev->queue)) {
173 spin_unlock_irqrestore(&eptdev->queue_lock, flags);
175 if (filp->f_flags & O_NONBLOCK)
178 /* Wait until we get data or the endpoint goes away */
179 if (wait_event_interruptible(eptdev->readq,
180 !skb_queue_empty(&eptdev->queue) ||
184 /* We lost the endpoint while waiting */
188 spin_lock_irqsave(&eptdev->queue_lock, flags);
191 skb = skb_dequeue(&eptdev->queue);
192 spin_unlock_irqrestore(&eptdev->queue_lock, flags);
196 use = min_t(size_t, iov_iter_count(to), skb->len);
197 if (copy_to_iter(skb->data, use, to) != use)
205 static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
206 struct iov_iter *from)
208 struct file *filp = iocb->ki_filp;
209 struct rpmsg_eptdev *eptdev = filp->private_data;
210 size_t len = iov_iter_count(from);
214 kbuf = kzalloc(len, GFP_KERNEL);
218 if (!copy_from_iter_full(kbuf, len, from)) {
223 if (mutex_lock_interruptible(&eptdev->ept_lock)) {
233 if (filp->f_flags & O_NONBLOCK) {
234 ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
238 ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
242 mutex_unlock(&eptdev->ept_lock);
246 return ret < 0 ? ret : len;
249 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
251 struct rpmsg_eptdev *eptdev = filp->private_data;
257 poll_wait(filp, &eptdev->readq, wait);
259 if (!skb_queue_empty(&eptdev->queue))
260 mask |= EPOLLIN | EPOLLRDNORM;
262 mask |= rpmsg_poll(eptdev->ept, filp, wait);
267 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
270 struct rpmsg_eptdev *eptdev = fp->private_data;
272 if (cmd != RPMSG_DESTROY_EPT_IOCTL)
275 return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
278 static const struct file_operations rpmsg_eptdev_fops = {
279 .owner = THIS_MODULE,
280 .open = rpmsg_eptdev_open,
281 .release = rpmsg_eptdev_release,
282 .read_iter = rpmsg_eptdev_read_iter,
283 .write_iter = rpmsg_eptdev_write_iter,
284 .poll = rpmsg_eptdev_poll,
285 .unlocked_ioctl = rpmsg_eptdev_ioctl,
286 .compat_ioctl = compat_ptr_ioctl,
289 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
292 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
294 return sprintf(buf, "%s\n", eptdev->chinfo.name);
296 static DEVICE_ATTR_RO(name);
298 static ssize_t src_show(struct device *dev, struct device_attribute *attr,
301 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
303 return sprintf(buf, "%d\n", eptdev->chinfo.src);
305 static DEVICE_ATTR_RO(src);
307 static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
310 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
312 return sprintf(buf, "%d\n", eptdev->chinfo.dst);
314 static DEVICE_ATTR_RO(dst);
316 static struct attribute *rpmsg_eptdev_attrs[] = {
322 ATTRIBUTE_GROUPS(rpmsg_eptdev);
324 static void rpmsg_eptdev_release_device(struct device *dev)
326 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
328 ida_simple_remove(&rpmsg_ept_ida, dev->id);
329 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
333 static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev,
334 struct device *parent)
336 struct rpmsg_eptdev *eptdev;
339 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
341 return ERR_PTR(-ENOMEM);
344 eptdev->rpdev = rpdev;
346 mutex_init(&eptdev->ept_lock);
347 spin_lock_init(&eptdev->queue_lock);
348 skb_queue_head_init(&eptdev->queue);
349 init_waitqueue_head(&eptdev->readq);
351 device_initialize(dev);
352 dev->class = rpmsg_class;
353 dev->parent = parent;
354 dev->groups = rpmsg_eptdev_groups;
355 dev_set_drvdata(dev, eptdev);
357 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
358 eptdev->cdev.owner = THIS_MODULE;
363 static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpmsg_channel_info chinfo)
365 struct device *dev = &eptdev->dev;
368 eptdev->chinfo = chinfo;
370 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
373 dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
375 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
379 dev_set_name(dev, "rpmsg%d", ret);
381 ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
385 /* We can now rely on the release function for cleanup */
386 dev->release = rpmsg_eptdev_release_device;
391 ida_simple_remove(&rpmsg_ept_ida, dev->id);
393 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
401 int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
402 struct rpmsg_channel_info chinfo)
404 struct rpmsg_eptdev *eptdev;
407 eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
409 return PTR_ERR(eptdev);
411 ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
415 EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
417 static int rpmsg_chrdev_init(void)
421 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
423 pr_err("failed to allocate char dev region\n");
429 postcore_initcall(rpmsg_chrdev_init);
431 static void rpmsg_chrdev_exit(void)
433 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
435 module_exit(rpmsg_chrdev_exit);
437 MODULE_ALIAS("rpmsg:rpmsg_chrdev");
438 MODULE_LICENSE("GPL v2");